Error installing qtService help into assistant

I got the Qt Solutions from http://qt.gitorious.org/qt-solutions, and have a trouble trying to install its docs into assistant - I can see documentation menu, but page text is not displaying.

What I have done:

D:\WORK\Repos\qt-solutions\qtservice\doc\html>qhelpgenerator qtservice.qhp -o qtservice.qch
Building up file structure...
Insert custom filters...
Insert help data for filter section (1 of 1)...
Inser开发者_运维知识库t files...
Insert contents...
Insert indices...
Documentation successfully generated.

D:\WORK\Repos\qt-solutions\qtservice\doc\html>assistant -register qtservice.qch

Assistant says that documentation succesfully imported, but shows only menu headers (no html help texts). qtservice.qch has a size of 53 kb, so I think html was succesfully embedded in it.

My QT version is 4.6.3, running on WinXP SP3.

This works with Qt 4.7.1 (running on Vista), but does not work with 4.6.2 on the same machine. I assume the help files use features that were not supported in Qt 4.6.